Microtome stage



Dec. 22, 1959 J. BLUM MICROTOME STAGE 2 Sheets-Sheet 1 Filed Oct. 1, 1957 ATTORNEY Dec. 22, 1959 J. BLUM 2,918,334

MICROTOME STA/CE Filed Oct. 1, 1957 2 Sheets-Sheet 2 5/ 5 EIE.

INVENTOR 55 54 Jase; 540M 56 52 QATTQRNEY Patented Dec. 22, 1959 MICROTOME STAGE Josef Blum, Norwalk, Conn., assignor to Ivan Sorvall, Inc., Norwalk, Conn., a corporation of New York Application October 1, 1957, Serial No. 687,484

8 Claims. (Cl. 30859) This invention relates generally to precision instruments, and more particularly to improved movable and automatically compensating support structures for microtome knife holders or the like.

In my copending application Serial No. 500,110, filed April 8, 1955, now Patent 2,822,726, relating to microtomes, there is disclosed and described a knife holder stage which is slidably movable upon a platform which in turn is slidably movable upon the rails of a cast frame. In that application the upper and lower surfaces of the movable platform are ground or lapped and the surfaces of the rails also are ground or lapped in order to ensure stability for the knife holder stage. Nevertheless, wear and galling that occur between the various components necessitates the regrinding or relapping of their'bearingsurfaces in order to provide smooth sliding operation relative to each other and to provide a secure and stable foundation for the knife holder.

In order to obviate the foregoing disadvantages, 1 provide an improved structure for the microtome whereby any dimensional variations that may result from wear or other causes are compensated for by an automatically adjusting support system incorporated into the platform so that stability of the knife holder relative to the cast frame will be insured. This is accomplished by provid ing a pair of spaced apart steel pads on the respective lower and upper surfaces of the platform at one end thereof, while at the other end a pivoting rocker bar permits the stage to adjust itself to the platform and permits the platform to adjust itself. to the rails, thereby forming a universal compensating adjustment means between the. rails of the base and the knife supporting stage. I

Still other objects and advantages of my invention will be apparent from the specification.

The features of novelty which I believe to be characteristic of my invention are set forth herein and will best be understood, both as to their fundamental principles and as to their particular embodiments, by reference to the specification and accompanying drawings, in which:

Figure l is a fragmentary'side elevation of a microtome showing the positioning platform of the present invention, some parts being shown in phantom outline and others in cross-section;

Fig. 2 is a section view taken on line 2-2 of Fig. l, somepartsbeing shown in elevation;

Fig. 3 is an enlarged, partly exploded top perspective view of the platform;

Fig. 4 is a greatly enlarged, partly broken away, section view taken on line 4-4 of Fig. 1, some parts being omitted; and

Fig. 5 is a greatly enlarged fragmentary section view, partly in elevation, taken on line 5-5 of Fig. 2.

Referring now to the drawings in detail, and particularly to Figs. 1 and 2, there is shown a portion of a microtome base 11, formed of a casting of aluminum, steel or the like, the upper portion of which terminates in a pair of parallel horizontal rails 12 and 13 having" ground or lapped surfaces 14 and 15, respectively (Fig. 4). Movable slidably upon said rails is a generally rectangular block platform 16 having a forward extension 17 to which is attached an upwardly extending. bracket 18., Platform 16 slidably supports an upper. stage 21 made of a suitable. metal casting. Stage 21 has.

an upwardly extending bracket 22 which supports a microtome knife 23 by suitable means such as described.

in said copending application.

Platform 16 which is made of a suitable casting such as aluminum, steel or the like, has a pair of spaced.

apart vertical drill holes 25 and 26 near the forward end thereof (Figs. 2 and 4). Saiddrill holes serve as guides for the .countersinking of recesses 27 and 28 and recesses 31 and 32 at the upper and lower surfaces 33 and34, respectively, of platform 16. Recesses 2 7, 28, 31 and 32' accommodate substantially circular pads 36, 37, 38 and 39, respectively, made of suitably hardened stainlesssteel or the like. Each of said pads has an annular chamfer 41 whose shoulder 42 is recessed below its respective surface of platform 16. Pads 36, 37, 38 andi39 may be secured into their respective apertures by any suitable means, but in the embodiment shown in the drawing the surfaces of platform 16 are staked around said pads, as indicated by annular recesses 43, whereby the metal substance of the platform flows partially over the chamfers and secures the pads firmly in position.

The outer horizontal bearing surfaces 46, 47, 43 and 49 ofpads 36, 37, 38 and 39, respectively, extend between five to ten thousandths of an inch beyond the respective upper and lower surfaces 33 and34 of platform 16, as shown in somewhat exaggerated. detail in Fig. 4.

Bearing surfaces 48 and 49 of pads 38 and 39 are slidably movable over surfaces 14 and 15 of rails 12 and 13, respectively, while the lower surface of stage 21 is slidably movable over bearing surfaces 46 and 47 of pads 36 and 37; The bearing surfaces of all of said pads are ground'or lapped in order to provide smoothly slidable operation. Pads 36, 37', 38 and 39 are made of a suitable material such as stainless steel, nylon, Teflon or. other metalalloy or plastic which affords the lowest.

frictional characteristics relative to the materials of which stage;21' and rails 12 and 13 are made.

At the rear portion of platform 16 there is a lateral elongated aperture 51 (Figs. 2,3 and 5), which accommodates rocker bar 52whose length and width are somewhat less than those ofthe aperture.

aperture by means of pin 53 which extends through longitudinal apertures 54 and 55 of platform 16 and through aperture 56' of said rocker bar. The upper surface 57 of rocker bar 52 has a convex curvature, the highest extremity of 'which extends between five to ten thousandths of an inch above the surface of platform 16. Rocker bar 52alsohas a pair of downwardly extending feet 58 and 59 whose bottom surfaces extend from five to" ten thousandths of an inch below the bottom surface of platform 16 and slidably rest on rails 12. and 13.

Rocker bar 52 is made of. stainless steel, nylon, or

other suitable. metal, alley or plastic, which affords the lowest frictional. characteristics relative to the materialof which rails 12 and 13 are made, so that a smoothsliding operation is obtained. a

It is evident from the foregoing description that any variations in the surface levels of rails 12 and 13 will be compensated for by the pivotal motion of rocker bar 52 so that frequent regrinding or lapping of rail surfaces 14: and 15 are obviated, andthe stability of platform: 16, 1 on frame 11 is insured. Pin: 53, in combination with:

Rocker bar 52" is secured pivotally intermediate its ends within said pads 38 and 39, form a three point base for the adjustable pads 36 and 37 and the apex of rocker bar 52 whereby the stabilization of the stage is insured when it is moved into different positions relative to platform 16.

Platform 16 has a pair of rearwardly extending brackets 61, each provided with an aperture 62 which support a horizontal pin 63 to which adjustment bar 64 is pivotally connected. Platform 16 has a downwardly extending bracket 65 against whose rear surface the end of fine adjustment thumb screw 66 impinges, said thumb When it is necessary to locate knife 23 in the proper cutting position, platform 16 is moved manually to a suitable location relative to base 11 and is locked in position by manipulating handle 71 which operates a locking block (not shown), as described in said copending application. Thumb screw 67 is first rotated to provide for the initial coarse adjustment of stage 21 relative to platform 16. Thumb screw 66 is then rotated to actuate lever bar 64 to provide for the fine adjustment of the stage relative to platform 16 until the requisite positioning of knife 23 is achieved. When the cutting edge of knife 23 has been precisely located, stage 21 is secured fast to platform 16 by means of a lever and locking block arrangement (not shown) comparable to that disclosed in said copending patent application.

In some embodiments where base 11 has a unitary horizontal bearing surface instead of spaced apart rails 12 and 13, legs 58 and 59 of rocker bar 52 may be dispensed with and the lower surface of said bar may be arranged to extend slightly below the bottom surface of block 16, whereby the pivoting action of said bar compensates for any irregularities in the bearing surface of base 11.

In other embodiments, rocker bar 52 may be positioned with its legs extending above the upper surface of platform 16 and with the apex of its convex surface 57 extending below the bottom surface of said platform, provided base 11 has a unitary hor zontal bearing surface instead of spaced apart rails 12 and 13.

In further embodiments, where platform 16 itself respective upper and lower surfaces of said block, a lateral aperture at the other end of said block, a rocker bar pivotally mounted within said aperture, and a pair of spaced apart legs on the bottom of said rocker bar, the bottom surfaces of said legs extending a slight distance beyond the bottom surface of said block said rocker bar having a convex upper surface, the apex of said upper sur- 3 face extending a slight distance beyond the upper surface of said block.

2. A movable platform for a precision instrument or the like, comprising a block movable relative to a surface of the base of said instrument, a pair of spaced apart pads at one end of said block, the surface of slid pads extending slightly beyond the surface of said block, said pad surfaces bearing slidably against said base surface, a rocker bar pivotally mounted at the other end of said block, a pair of spaced apart legs on said rocker bar, the bottom surfaces of said legs extending a slight distance beyond said block surface, the pivotal action of said rocker bar being adapted to compensate for any irregularities in the base surface when said block is moved from one position to another relative to said base.

3. A precision instrument or the like, comprising a base, a platform movable relative to said base, a stage movable relative to said platform, a first pair of spaced apart pads on said platform, the surfaces of said pads extending slightly beyond one surface of said platform and bearing slidably along a surface of said base, a second pair of spaced apart pads on said platform, the surfaces of said second pair extending slightly beyond a second surface of said platform and bearing slidably along a surface of said stage, a pivoting member on said platform spaced apart from said two pairs of pads, said member having opposite surfaces extending slightly beyond respective surfaces of said platform and bearing respectively against said base and stage surfaces.

4. A precision instrument or the like, comprising a base, a stage movable relative to said base, a platform between said platform and said base, and together with said second pair of pads providing a bearing landing supports various instrument elements without any intermediary element such as stage 21, the upper convexsurface 57 of rocker bar 52 would be omitted, and platform 16 would be stabilized by the pivotal action between legs 58 and 59 of rocker bar 52 cooperating with pads 38 and 39.

In the specification, I have explained the principles of my invention, and the best mode in which I have contemplated applying those principles, so as to distinguish my invention from other inventions; and I have particularly pointed out and distinctly claimed the part, mode or combination which I claim as my invention or discovery.

While I have shown and described certain preferred embodiments of my invention, it will be understood that modifications and changes may be made without departing from the function and scope thereof, as will be clear to those skilled in the art.

I claim:

1. A movable platform for a microtome or the like, comprising a block, an upper and a lower surface on said block, a pair of spaced apart recesses in the lower surface and in the upper surface at one end of said block, a pad mounted in each of said recesses, the outer surface of each of said pads extending a slight distance beyond the between said platform and said stage, both of said bearing landings being adapted to compensate for any irregularities in the bearing surfaces of said base and said stage.

. a support stage movable over said platform, means for adjusting the position of said platform relative to said base, means for adjusting the position of said stage relative to said platform, a first pair of spacci apart pads at one end of said platform, the surface of each of said pads extending slightly beyond a first surface of said platform and adapted to move slidably over a corresponding rail of said base, a second pair of spaced apart pads at the same end of said platform, the surfaces of said pads extending slightly beyond a second surface of said platform and bearing slidably against a surface of said stage, a pivoting rocker bar at the other end of said platform, a pair of spaced apart legs on said rocker bar, the surface of said legs extending slightly beyond said first surface of said platform, said leg surfaces each bearing slidably upon a corresponding base rail, a convex surface on said rocker bar, the apex of said rocker bar surface extending a slight distance beyond the second E surface of said platform and bearing against the surface of said stage.

6. A structure for a precision instrument or the like, comprising a first element, a second element adapted to be adjustably positioned relative to said first element, a third element positioned between said first and second elements and adjustably movable relative thereto, a first set of three spaced apart bearing elements on one surface of said third element against which said first element sliclably moves, a second set of three spaced apart bearing elements on another surface of said third element against which said second element slidably moves, one of said bearing elements of each of said sets of bearing elements being a portion of a single pivotable element connected to said third element.

7. A structure according to claim 6 wherein the three spaced apart bearing elements in each set are in triangular array.

8. A structure according to claim 6 wherein the pivotable element comprises a rocker bar having a curved surface against which said first element bears, and a pair of foot extensions against which said second element bears.

References Cited in the file of this patent UNITED STATES PATENTS 673,406 Midboe May 7, 1901 1,429,557 Bauer Sept. 19, 1922 1,429,617 Muller Sept. 19, 1922 

